@mixin content_fontSize($base_size:12px) {
    @media screen and (max-width: 320px) {
        font-size: $base_size;
    }

    @media screen and (min-width:321px) and (max-width:375px) {
        font-size: $base_size + 2;
    }

    @media screen and (min-width:376px) {
        font-size: $base_size + 4;
    }
}
